CEACAM5 and gastric cancer: Univariate Cox proportional hazards analyses revealed that history of GC operation (yes vs. no, P < 0.001), CEA level (<5 vs. ≥5 U/ml, P = 0.071), CA199 level (<37 vs. ≥37 U/ml, P = 0.001), and NLR (<2.8 vs. ≥2.8, P < 0.001) were significantly associated with OS (Supplementary Table 1).